Magnetic ratchet mechanism for wrenches and the like



R. E. BADGER May 10, 1966 MAGNETIC RATCHET MECHANISM FOR WRENCHES ANDTHE LIKE Filed NOV. 6, 1963 INVENTOR.

ATTORNEY United States Patent 3,250,157 MAGNETIC RATCHET MECHANISM FORWRENCHES AND THE LIKE Robert E. Badger, Kenosha, Wis.,- assignor toSnap-On Tools Corporation, Kenosha, Wis., a corporation of DelawareFiled Nov. 6, 1963, Ser. No. 321,954 8 Claims. (Cl. 8163) This inventionrelates to ratchet wrenches and more particularly to magneticallycontrolled directional pawl type ratchet wrenches, although theteachings thereof may be employed with equal advantage for otherdevices.

It contemplates more especially the provision of magneticallydisplaceable ratchet pawl control devices used particularly for but notlimited to ratchet wrenches to displace the pawl in relation to theratchet wheel so that the ratcheting action can be effected in oppositedirections, although this concept has a much wider application tomechanical devices of many different types and uses.

Ratchet wrenches have long been used and various mechanical expedientshave been resorted to for the purpose of shifting the position of a pawlin relation to the ratchet wheel so that the ratcheting action can beresorted to for tightening and loosening nuts and other fasteners. Suchmechanical pawl displacing expedients are satisfactory for predeterminedperiods, but are subject to wear and frictional problems whichaccumulate dirt,

oil debris and otherwise become ineflicient after extended periods ofuse. With the concept of providing magnetic pawl shift controls, Wear isreduced to a minimum and malfunctioning due to-dirt-and oil debrisaccumulations, do not retard the effectiveness there o-f. At least, theefficient functioning life of the ratchet is extended and moredependable operation over a longer period is attained.

One object of the present invention is to provide an improved ratchetpawl shifting device for wrenches and the like.

vAnother object is to provide an improved magnetic ratchet pawl shiftmechanism that reduces wear and extends the normal eflicient operatinglife of ratchet wrenches and the like.

Still another object is to provide an improved magnetic pawl control fordetermining the direction of ratcheting in a clockwise orcounterclockwise direction.

A further object is to simplify the construction and operation of wrenchratchet pawls and the like.

A still further object is to provide more efiicient double directionalratchet pawls in wrenches and the like.

Still a further object is to provide an improved magnetic double pawlshifting device wherein wear is reduced to a minimum and the requirementfor lubrication is negligible so that dirt and oil debris will notaccumulate toimpair the operation of the ratcheting mechanism.

Other objects and advantages will appear from the following descriptionof an illustrated preferred embodiment of the invention.

FIGURE 1 is a perspective view of a ratchet wrench of the type to whichmagnetically controlled directional pawls may be embodied in accordancewith the teachings of the present invention.

FIGURE 2 is a sectional view in elevation taken transversely through thepawl mechanism and lever control of FIGURE 1. I

FIGURE 3 is a fragmentary perspective view of the magneticallycontrolled directional pawl mechanism illustrated in FIGURE 2.

FIGURE 4 is a fragmentary plan View of the pawl and ratchet mechanismviewed with the wrench housing 3,259,157 Patented May 10, 1966 icemagnetically controlled pawl and ratchet mechanism embodying features ofthe present invention.

The structure selected for illustration is not intended to serve as alimitation upon the scope or teachings of the invention, but is merelyillustrative thereof. There may be considerable variations andadaptations of all or part of the teachings depending upon the dictatesof commercial practice. The present embodiment comprises an elongatedhandle member '10 of my suitable shape and proportion to apply a turningmovement thereto and to its enlarged head portion usually formedintegral therewith to provide a suitable casing 11, in this instance ofarcu'ate or cylindrical configuration. The casing 11 is chambered forthe reception of ratcheting instrumentalities to be hereinafterdescribed.

The casing 11 has a circular chamber 12 to freely receive a somewhatsmaller work engaging member 13 including a drive shaft, ratchet wheeland a pawl as will more specifically appear from the description tofollow. The work engaging member 13 has a trunnion 14 extending throughthe casing bottom 16 which confronts a closure plate (not shown) that ispress-fitted into and corresponds in shape to the casing opening 15 thatis slightly smaller to provide for a tight press-fit of the closureplate therewith. The closure plate affords a tight sealed fit with thecasing opening 15 and also serves as a bearing for the work engagingmember 13 that has a polygonal geometrically shaped stub .shaft 17 towhich a wrench socket is detachably associated for retention by astandard spring impelled ball detent that enables differently sizedwrench sockets to be used therewith for rotation intermittently throughthe manually applied turning moment on the wrench handle member 10. Thisenables variously sized nuts or other fasteners to be tightened andloosened through a ratcheting action as will presently appear.

In order to ratchet the fastener for a tightening or looseningoperation, the work engaging member 13 is provided with a ratchet wheel18 having a series of uniformly spaced ratchet teeth 19 on the peripherythereof confined within the casing chamber 12 (FIGURE 4) to cooperatewith a pawl 20. The pawl 20 is, in this instance,

circularly shaped to provide opposed double teeth 21-22 on eachspacedpoint of the pawl 20 that is, for the most part, of circularconfiguration interrupted along a short arc to present the opposed teeth21-22 and to fit into the bottom of the pear-shaped casing opening 15having an enlarged portion thereof of generally circular shape. Theopposed pawl teeth 21-22 on each end of the circular pawl body 20, areadapted to engage the ratchet teeth 19 when rot-atively shifted to oneor the other of two extreme positions, namely the extreme clockwise orcounterclockwise positions when one or the other of the teeth 21-22 meshwith the ratchet wheel teeth 19 to determine the direction of ratchetingfor either tightening or loosening the fasteners as the case may be andthe operation requires.

The rotary displacement of the pawl 20 is effected about its axialprojecting pin mount 23 journalled, in this instance, in the casingclosure plate press-fitted into the casing opening 15. The pawl 20 hastwo cylindrical magnets 24-25 press-fitted into brass or other non-mag:netic sleeves 26-27 which, in turn, are press-fitted into recesses 28-29provided in the body of the pawl 20 to present a north and south endpole, respectively, to cooperate with opposite magnetic poles on a pawlposition control to be presently described. The pawl 20 is magneticallyactuated to oscillate about its pin 23 to cause pawl teeth 21 or 22 toengage the pawl teeth 19 for fastening or'lo osening nuts or otherfasteners with a ratcheting turning action. The positioning of the pawl20 is accomplished by means of confronting spaced cylindrical mag- 3nets 3031 which are opposite in polarity to the magnets 24-25 toestablish an effective attractive magnetic force therebetween as willpresently appear to shift the pawl 20.

To this end, the magnets 30-31 are mounted in a magnetically shieldedbody 36 and joined in a magnetic configuration by a bar plate 32provided with a center pin 33 for journalled connection through thecasing bottom 16 for attachment of an externally accessible lever 34exteriorly mounted to a pivot in a recessed casing wall chamber 35 toprovide a flush shifting device that will not obstruct the ratchetingaction in close quarters. It is through the exteriorly accessible lever34 that the double toothed pawl 2%) is actuated and positionedmagnetically without any drag or wear between the pawl 20 and theactuator 33-34. As shown, the actuator magnets 3041 are preferablythough not essentially mounted in the body member 36 which could beprovided with a projecting nib or fulcrum point 37 cooperating with aminute recess axially indented within the pawl mounting pin 23 to pivotrelative thereto with minimum friction. Thus, there is no physicalconnection between the pawl body 20 and the directional shiftingmechanism 3344-36 so that lubrication and the accumulation of dirt andoil debris is not a factor that ultimately impairs the operation of theusual type of ratchet mechanisms, the latter involving mechanicalsprings to maintain the :pawl teeth in operative engagement with theratchet teeth.

In the modified embodiment illustrated in FIGURE 5, the pawl 20'consists of angular arms having a pin mount 23' at their juncture topresent pawl teeth 21-22'. Magnets 2425 are mounted in the free pawltooth ends of the pawl arms 20'20' to cooperate with a bar magnet 30'presenting opposite poles relative to the pawl arm magnets 24-25'. 'Apin 33' pivotally mounts the bar magnet 30 to actuate the pawl 20' sothat teeth 21' or 22' engage the ratchet wheel teeth 19'. Otherstructural arrangements can be used to accomplish the same concept andprinciple of operation for positioning the pawl teeth relative to theratchet teeth to intermittently tighten or loosen fasteners as required.The on-oif position of the pawl shifting device may be inscribed on thecasing bottom 16 near the lever 34 so that the user will not be confusedor entail any delay in determining the direction desired for anyparticular job.

It will be apparent from the foregoing description that the pawlmechanism whether or not single or double, is magnetically controlled asto positioning without any mechanical connection between the positionpawl shifter and the pawl or |pawls themselves so that wear isnegligible and the accumulation of dirt, oil, grease or other debriswill not interfere with the functioning therebetween. Friction betweenthe pawl shifter and the pawls is eliminated, and each of these elementsis free from the other as to any physical connection. Each of theelements, namely the pawls and the pawl shifter are physically mountedin the housing independently of each other and without any physicalengagement or attachment therebetween. This prolongs the life andoperating action of the ratchet mechanism and insures dependableoperation over an extended peniod.

While I have illustrated and described a preferred embodiment of theinvention, it must be understood that the invention is capable ofconsiderable variation and modification without departing from thespirit of the invention. 1, therefore, do not wish to be limited to theprecise details of constructi n l forth, but desire to 4 avail ourselvesof such variations and modifications as come within the scope of theappended claims.

Iclaim:

-1. A ratchet mechanism comprising a handle member, a casing formed onthe end of said handle member, a work engaging member journalled forrotation in said casing, a ratchet wheel on said work engaging memberwithin the confines of said casing, a pawl journalled in said casing sothat one or the other of said pawl teeth mesh with said ratchet teeth tointermittently tighten or loosen fasteners when in operative registrywith said work engaging member, a pawl shifting control exteriorlyaccessible relative to said casing and magnetically connected to saidpawl, and magnets mounted in said pawl and shifting control in closespaced proximity within said casing to cause said pawl to follow theshifted position of said shifting control to either extreme position ofadjust ment.

2. A ratchet mechanism defined in claim 1 wherein the pawl is pivoted insaid casing and the shift control is pivotally mounted to a wall of saidcasing without a direct mechanical connection between said pawl and saidshift control.

3. A ratchet mechanism defined in claim 2 wherein the magnets in saidpawl and said shifting control are of opposite polarity.

4. A ratchet mechanism defined in claim 1 wherein the magnets in saidpawl and said shifting control are of cylindrical configuration andmounted in aligned close spaced proximity to present magnetic poles ofopposite polarity.

5. A ratchet mechanism defined in claim 4 wherein the cylindricalmagnets are press-fitted into non-magnetizable sleeves to confine thelines of magnetic flux to provide more effective attraction andrepulsion between said aligned magnets.

6. A ratchet mechanism defined in claim 3 wherein the :pawl and shiftingcontrol are journalled in opposite walls of the casing.

7. A ratchet mechanism defined in claim 2 wherein the pawl is multipletoothed to enable opposite directional ratcheting.

8. A ratchet mechanism for wrenches and the like comprising a casing,means for manually oscillating said casing, a work engaging memberjournalled for rotation in said casing and projecting therefrom, aratcheting mechanism in said casing, pawl means for cooperating withsaid ratcheting mechanism to intermittently turn said work engagingmember in one direction or an opposite direction responsive tooscillating said casing, pawl shifting means mounted in said casing inspaced relation to said pawl means without any direct physicalconnection the-rebetween, and magnetic means on said shifting and pawlmeans to render said pawl means operatively responsive to said shiftmeans to control the directional ratcheting of said work engagingmember.

References Cited by the Examiner UNITED STATES PATENTS 2,750,828 6/ 1956Wendlin g 8'1-125 FOREIGN PATENTS 61,663 12/1954 France.

WILLIAM FELDMAN, Primary Examiner.

JAMES L. JONES, JR., Examiner.

1. A RATCHET MECHANISM COMPRISING A HANDLE MEMBER A CASING FORMED ON THEEND OF SAID HANDLE MEMBER, A WORK, ENGAGING MEMBER JOURNALLED FORROTATION IN SAID CASING, A RATCHET WHEEL ON SAID WORK ENGAGING MEMBERWITHIN THE CONFINES OF SAID CASING, A PAWL JOURNALLED IN SAID CASING SOTHAT ONE OR THE OTHER OF SAID PAWL TEETH MESH WITH SAID RATCHET TEETHINTERMITTENTLY TIGHTEN OR LOSSEN FASTENERS WHEN IN OPERATIVE REGISTRYWITH SAID WORK ENGAGING MEMBER, A PAWL SHIFTING CONTROL EXTERIORLYACCESSIBLE RELATIVE TO SAID CASING AND MAGNETICALLY CONNECTED TO SAIDPAWL, AND MAGNETS MOUNTED IN SAID PAWL AND SHIFTING CONTROL IN CLOSESPACED PROXIMITY WITHIN SAID CASING TO CAUSE SAID PAWL TO FOLLOW THESHIFTED POSITION OF SAID SHIFTING CONTROL TO EITHER EXTREME POSITON OFADJUSTMENT.